Antitheft system

ABSTRACT

An anti-theft system includes an engine control unit  4  for starting an engine  2  in response to the on operation of an engine key  5  only when an engine start enabling signal is supplied thereto, portable communication equipment  7  which is used for short-distance wireless communications, and to which peculiar ID information is provided, and vehicle-mounted communication equipment  6  having an ID information storage unit  6   a  for registering the peculiar ID information provided to the portable communication equipment  7  thereinto, for acquiring the ID information from the portable communication equipment  7  via short-distance wireless communications regardless of whether the on operation of the engine key has been carried out, and for stopping the supply of the engine start enabling signal to the engine control unit  4  when the acquired ID information does not match with the ID information registered into the ID information storage unit  6   a.

FIELD OF THE INVENTION

The present invention relates to an anti-theft system. Moreparticularly, it relates to a technology for implementing theftprevention using portable communication equipment.

BACKGROUND OF THE INVENTION

Conventionally, a security system for vehicles which protects a vehiclefrom theft by identifying a person who is allowed to use the vehicle(referred to as an “authorized vehicle user” from here on) usingportable communication equipment is known (for example, refer to patentreference 1). In this security system for vehicles, the same IDinformation as ID information given to the portable communicationequipment which the authorized vehicle user is having is registered intoa memory in vehicle-mounted equipment. When a main power supply forvehicles is turned on by an ignition switch, the vehicle-mountedequipment carries out short distance wireless communications with theportable communication equipment and then checks to see whether the IDinformation stored therein matches with that given to the portablecommunication equipment. When determining that the ID information storedtherein does not match with that given to the portable communicationequipment, the vehicle-mounted equipment outputs an alarm signalindicating an instruction for prohibiting an engine ECU from staring theengine to the engine ECU and also sends alarm information, byway of avehicle-mounted communication terminal which can carry out long distancecommunications, to the portable communication equipment which theauthorized vehicle user is having.

Furthermore, when the portable communication equipment which theauthorized vehicle user is having receives the alarm information, therelated art security system for vehicles can perform a drivingprohibition control operation of switching the vehicle to a drivingimpossible state in which the vehicle cannot be driven on condition thatthe vehicle is stopping. When a proper user does not exist in an areawhere the vehicle-mounted communication terminal carries out shortdistance communications, the related art security system can enable adoor locking mechanism for vehicles to carry out a locking operationthrough a locking/unlocking device. When receiving an acknowledgerequest signal from the portable communication equipment which theauthorized vehicle user is having, the related art security systemanswers a status signal indicating whether the vehicle is locked orunlocked back to the portable communication equipment through thevehicle-mounted communication terminal. Then, when the authorizedvehicle user recognizes that he or she has forgotten to lock thevehicle, he or she can manipulate the portable communication equipmentto make it send a locking command signal to the vehicle-mountedcommunication terminal and to make the door locking mechanism forvehicles to lock the vehicle.

Patent reference 1: JP,2002-269663,A

A problem with the above-mentioned related art security system forvehicles is however that since it starts a process of checking to seewhether or not the vehicle is stolen when a main power supply forvehicles is turned on in response to a switching signal from an ignitionswitch, the related art security system cannot take measures against acase of starting the engine by directly wiring the ignition to a powersupply without manipulating the ignition switch.

There have been provided requests to make it possible to cause theengine to start according to a special procedure even when theauthorized vehicle user is not having the portable communicationequipment, when the authorized vehicle user cannot use the portablecommunication equipment because the battery is dead or a failure occursin the portable communication equipment, or when the ID informationgiven to the portable communication equipment is changed because ofreplacement of the portable communication equipment with a new model ofportable communication equipment. There have also been requests toperform registration and cancellation of the registration of the IDinformation of the portable communication equipment, and to make achange or the like to the ID information, with easy operations.

The present invention is made in order to solve the above-mentionedproblems and to respond to the above-mentioned requests, and it istherefore an object of the present invention to provide an anti-theftsystem which can surely prevent any person other than an authorizedvehicle user from starting the engine of a vehicle, thereby improvingsecurity against theft of the vehicle, and which makes it possible forthe user to easily perform an operation for theft prevention.

DISCLOSURE OF THE INVENTION

An anti-theft system in accordance with the present invention includes:an engine control unit for starting an engine in response to an onoperation of an engine key only when an engine start enabling signal issupplied thereto; portable communication equipment which is used forshort-distance wireless communications, and to which peculiar IDinformation is provided; and vehicle-mounted communication equipmenthaving an ID information storage unit for registering the peculiar IDinformation provided to the portable communication equipment thereinto,for acquiring the ID information from the portable communicationequipment via short-distance wireless communications regardless ofwhether the on operation of the engine key has been carried out, and forstopping the supply of the engine start enabling signal to the enginecontrol unit when the acquired ID information does not match with the IDinformation registered into the ID information storage unit.

When the ID information acquired from the portable communicationequipment via short-distance wireless communications does not match withthe ID information registered into the ID information storage unit, theanti-theft system stops the supply of the engine start enabling signalto the engine control unit even if the on operation of the engine key isnot carried out. Therefore, any parson who is not carrying theregistered portable communication equipment cannot start the engine evenif he or she tries to start the engine by directly wiring the ignitionto a power supply without manipulating the engine key. As a result, theanti-theft system can prevent theft of the vehicle resulting from loss,theft, illegal duplication, or the like of the engine key, therebyimproving security against theft of the vehicle.

BRIEF DESCRIPTION OF THE FIGURES

[FIG. 1] FIG. 1 is a block diagram showing the structure of ananti-theft system in accordance with embodiment 1 of the presentinvention;

[FIG. 2] FIG. 2 is a block diagram showing the structure of ananti-theft system in accordance with embodiment 2 of the presentinvention;

[FIG. 3] FIG. 3 is a block diagram showing the structure of ananti-theft system in accordance with embodiment 3 of the presentinvention;

[FIG. 4] FIG. 4 is a block diagram showing the structure of ananti-theft system in accordance with embodiment 4 of the presentinvention;

[FIG. 5] FIG. 5 is a block diagram showing the structure of ananti-theft system in accordance with any one of embodiments 5, 6, and 7of the present invention;

[FIG. 6] FIG. 6 is a block diagram showing the structure of ananti-theft system in accordance with embodiment 8 of the presentinvention;

[FIG. 7] FIG. 7 is a block diagram showing the structure of ananti-theft system in accordance with any one of embodiments 9 and 10 ofthe present invention;

[FIG. 8] FIG. 8 is a block diagram showing the structure of ananti-theft system in accordance with embodiment 11 of the presentinvention;

[FIG. 9] FIG. 9 is a block diagram showing the structure of ananti-theft system in accordance with any one of embodiments 12 and 13 ofthe present invention;

[FIG. 10] FIG. 10 is a block diagram showing the structure of ananti-theft system in accordance with embodiment 14 of the presentinvention; and

[FIG. 11] FIG. 11 is a block diagram showing the structure of ananti-theft system in accordance with embodiment 15 of the presentinvention.

PREFERRED EMBODIMENTS OF THE INVENTION

In order to explain the invention in greater detail, the preferredembodiments of the invention will be explained below with reference tothe accompanying figures.

Embodiment 1

FIG. 1 is a block diagram showing the structure of an anti-theft systemin accordance with embodiment 1 of the present invention. Thisanti-theft system is provided with an engine 2, a battery 3, an enginecontrol unit 4, an engine key 5, and vehicle-mounted communicationequipment 6 which are mounted in a vehicle 1, and portable communicationequipment 7 which an authorized vehicle user is having.

The start, stop, etc. of the engine 2 are controlled according to both apower source supplied thereto from the battery 3 and an engine controlsignal supplied from the engine control unit 4.

The engine control unit 4 generates the engine control signal based onboth an instruction generated when the engine key 5 is manipulated andan engine start enabling signal sent thereto from the vehicle-mountedcommunication equipment 6, and sends them to the engine 2. To be morespecific, the engine control unit 4 receives the instruction generatedby the on operation of the engine key 5 so as to generate the enginecontrol signal for starting the engine 2 only when the engine startenabling signal is sent thereto from the vehicle-mounted communicationequipment 6. Therefore, the engine control unit ignores the on operationof the engine key 5 in a state in which the engine start enabling signalis not sent thereto from the vehicle-mounted communication equipment 6.

The vehicle-mounted communication equipment 6 is comprised of, forexample, a car audio device having a short-distancewireless-communications function. This vehicle-mounted communicationequipment 6 is provided with an ID information storage unit 6 a. Inorder to enable the vehicle-mounted communication equipment to determinewhether or not the communication partner is the portable communicationequipment 7 which the authorized vehicle user is having, ID informationuniquely given to the portable communication equipment 7 is registered(or memorized) into the ID information storage unit 6 a. The car audiodevice is provided with two or more operation buttons (not shown) forcontrolling its audio function. These operation buttons are also used inorder for the authorized vehicle user to register or erase the IDinformation, as will be mentioned later in detail. Instead of the caraudio device, either a car navigation apparatus or anothervehicle-mounted apparatus can be used as the vehicle-mountedcommunication equipment 6.

This vehicle-mounted communication equipment 6 runs from a power source(what is called +B power supply) supplied directly thereto from thebattery 3. Therefore, even before the on operation of the engine key 5is carried out, the vehicle-mounted communication equipment can operate.As an alternative, the power source can be directly supplied from thebattery 3 not to the whole of the vehicle-mounted communicationequipment 6, but only to a circuit of the vehicle-mounted communicationequipment 6 for implementing a theft prevention function. According tothis structure, the exhaustion of the battery 3 can be reduced comparedwith the case where the power source is supplied to the whole of thevehicle-mounted communication equipment 6.

For the short-distance wireless communications, electric waves in a 2.4GHz band called the ISM band are used and a wireless LAN or a radiotransmission system according to Bluetooth standards, which have beendeveloped as short distance communication technologies that provide atransmission distance of about 10 to 100 meters and a transmission speedof about 1 to 11 Mbps, can be used.

The portable communication equipment 7 is comprised of a cellular phoneprovided with a short-distance wireless-communications function, and theID information peculiar to this cellular phone is stored in the portablecommunication equipment 7. As the portable communication equipment 7, atransportable apparatus provided with a short-distancewireless-communications function, such as a PDA or a notebook personalcomputer, can be used instead of the cellular phone.

Next, the operation of the anti-theft system in accordance withembodiment 1 of the present invention which is constructed as mentionedabove will be explained.

In a state in which the engine 2 is stopped, the vehicle-mountedcommunication equipment 6 to which the power source is supplied from thebattery 3 is on standby while determining whether the portablecommunication equipment (referred to the “registered portablecommunication equipment” from here on) 7 having the ID information whichmatches with the ID information registered into the ID informationstorage unit 6 a exists in a short-distance wireless communications areain which the registered portable communication equipment can carry outshort-distance wireless communications with the vehicle-mountedcommunication equipment. To be more specific, the vehicle-mountedcommunication equipment 6 tries to acquire the ID information from theportable communication equipment 7 which exists in the short-distancewireless communications area at predetermined intervals. Then, when theuser who is having the portable communication equipment 7 enters thevehicle 1, for example, the portable communication equipment 7 thereforeenters the short-distance wireless communications area, and thevehicle-mounted communication equipment can acquire the ID informationfrom the portable communication equipment 7, the vehicle-mountedcommunication equipment checks to see whether the acquired IDinformation matches with the ID information registered into the IDinformation storage unit 6 a.

When determining that the ID information acquired from the portablecommunication equipment 7 matches with the ID information registeredinto the ID information storage unit 6 a as the result of the checking,the vehicle-mounted communication equipment recognizes that theregistered portable communication equipment 7 exists in the area inwhich it can carry out short-distance wireless communications with thevehicle-mounted communication equipment. The vehicle-mountedcommunication equipment 6 then sends the engine start enabling signalshowing the fact to the engine control unit 4. In contrast, whendetermining that the ID information acquired from the portablecommunication equipment 7 does not match with the ID informationregistered into the ID information storage unit 6 a, or when failing toacquire the ID information from the portable communication equipment 7,the vehicle-mounted communication equipment recognizes that theregistered portable communication equipment 7 does not exist in the areain which it can carry out short-distance wireless communications withthe vehicle-mounted communication equipment. In this case, thevehicle-mounted communication equipment 6 does not send any engine startenabling signal showing that the registered portable communicationequipment can carry out short-distance wireless communications with thevehicle-mounted communication equipment to the engine control unit 4.

In response to the engine start enabling signal from the vehicle-mountedcommunication equipment 6, the engine control unit 4 enables the onoperation of the engine key 5. Therefore, when receiving an instructiongenerated by the on operation of the engine key 5 in this state, theengine control unit generates the engine control signal for starting theengine 2 and sends it to the engine 2. The function of starting theengine 2 when the user who is having the registered portablecommunication equipment 7 turns on the engine key 5 is thus implemented.

On the other hand, the engine control unit 4 disables the on operationof the engine key 5 in a state in which it has not received the enginestart enabling signal from the vehicle-mounted communication equipment6. Therefore, even if the engine control unit 4 receives an instructioncaused by the on operation of the engine key 5 in this state, it doesnot generate the engine control signal for starting the engine 2. Thefunction of prohibiting the engine 2 from being started even if the onoperation of the engine key 5 is performed by either a person who is nothaving the portable communication equipment 7 or a person who is havingportable communication equipment 7 having ID information which is notregistered into the ID information storage unit 6 a of thevehicle-mounted communication equipment 6 is thus implemented.

As previously explained, the anti-theft system in accordance withembodiment 1 of the present invention controls whether to enable the onoperation of the engine key 5 according to the engine start enablingsignal from the vehicle-mounted communication equipment 6 to which thepower source is always supplied, in contrast to a related art anti-theftsystem which starts a process of checking to see whether or not thevehicle is stolen in response to the on operation of the engine key 5which is compliant with the vehicle 1. Therefore, even if a person whois not having the registered portable communication equipment 7 tries tostart the engine without manipulating the engine key 5, e.g., bydirectly wiring the ignition to a power supply, he or she cannot startthe engine 2. The present embodiment can thus protect the vehicle fromtheft resulting from the loss, theft, illegal duplication, or the likeof the engine key 5, and therefore can improve security against theft ofthe vehicle.

Embodiment 2

An anti-theft system in accordance with embodiment 2 of the presentinvention is so constructed as to carry out short-distance wirelesscommunications using a radio transmission method compliant with theBluetooth standards.

FIG. 2 is a block diagram showing the structure of a registrationprevention system for vehicles in accordance with embodiment 2 of thepresent invention. This anti-theft system uses a vehicle-mountedBluetooth (BT) device 6 b provided with a Bluetooth interface instead ofthe vehicle-mounted communication equipment 6 of the anti-theft systemin accordance with embodiment 1, and uses a portable Bluetooth (BT)device 7 b provided with a Bluetooth interface instead of the portablecommunication equipment 7.

“BD_ADDR (a Bluetooth address)” which is defined according to theBluetooth standards is used as ID information. The other structure ofthe anti-theft system of this embodiment is the same as that of theanti-theft system in accordance with embodiment 1. A Bluetooth addressis uniquely assigned to every Bluetooth-mounted device. Therefore, whenshort-distance wireless communications are carried out using the radiotransmission method compliant with the Bluetooth standards, since aBluetooth address which is only one all over the world is used as IDinformation, the portable communication equipment 7 can be strictlydistinguished form any other portable communication equipment.

The Bluetooth standards used in this anti-theft system have thefollowing features.

(1) Electronic equipment which receives authentication according to theBluetooth standards can carry out short-distance wireless communicationsregardless of the type (e.g., a personal computer, a cellular phone, adigital camera, or the like) and manufacturer of the electronicequipment.

(2) A unique number (BD_ADDR) is assigned to a control IC mounted ineach electronic equipment.

(3) Each electronic equipment is wireless-connected to a master (MASTER)device while having a relationship between one of up to seven slave(SLAVE) devices and the master device.

(4) “Three sleep modes=which sometimes become search mode according tothe standards=low power consumption mode” are defined.

(5) A procedure for exchanging information including “BD_ADDR” and“corresponding specifications”, and, after that, determining whether toestablish a communication connection is adopted when establishing thecommunication connection. The master device is vested with the authorityto determine whether to establish a communication connection.

According to the above-mentioned features of the Bluetooth standards,the anti-theft system in accordance with embodiment 2 defines thevehicle-mounted BT device 6 b as “MASTER”, also defines the portable BTdevice 7 b as “SLAVE”, and carries out short-distance wirelesscommunications between the vehicle-mounted BT device 6 b and theportable BT device 7 b by using BD-ADDR as the ID information. Thevehicle-mounted BT device 6 b is set so as to operate in the sleep mode.

As previously explained, since the anti-theft system in accordance withembodiment 2 of the present invention uses the general-purpose Bluetoothstandards as the radio transmission method of carrying outshort-distance wireless communications. Therefore, low-cost componentscan be used as the components included in the anti-theft system, and theanti-bugging system can be formed at a low cost. Since thevehicle-mounted BT device 6 b is so constructed as to operate in thesleep mode, the power consumption of the vehicle-mounted BT device 6 bcan be reduced, and this results in reduction in the exhaustion of thebattery 3.

Embodiment 3

An anti-theft system in accordance with embodiment 3 of the presentinvention includes a door unlocking function in addition to thestructure of the anti-theft system in accordance with embodiment 1.

FIG. 3 is a block diagram showing the structure of the anti-theft systemin accordance with embodiment 3 of the present invention. Thisanti-theft system has a modified function corresponding to that of thevehicle-mounted communication equipment 6 of the anti-theft system inaccordance with embodiment 1, and additionally includes a vehiclecontrol unit 8 and a door unlocking mechanism 9. Hereafter, thedifference between this embodiment and embodiment 1 will be explainedmainly.

The vehicle-mounted communication equipment 6 generates an engine startenabling signal and sends it to an engine control unit 4, as mentionedabove, and also generates an unlocking enabling signal for permittingunlocking of doors of a vehicle 1 and sends it to the vehicle controlunit 8. The unlocking enabling signal is generated on the sameconditions as those on which the engine start enabling signal isgenerated.

The vehicle control unit 8 generates a door control signal in responseto the unlocking enabling signal sent thereto from the vehicle-mountedcommunication equipment 6, and sends it to the door unlocking mechanism9. The door unlocking mechanism 9 then unlocks the doors (not shown) inresponse to the door control signal sent thereto from the vehiclecontrol unit 8.

Next, the operation of the anti-theft system in accordance withembodiment 3 of the present invention which is constructed as mentionedabove will be explained.

In a state in which the engine 2 is stopped, the vehicle-mountedcommunication equipment 6 to which a power source is supplied from abattery 3 is on standby while determining whether registered portablecommunication equipment 7 exists in a short-distance wirelesscommunications area in which the vehicle-mounted communication equipmentcan carry out short-distance wireless communications with the registeredportable communication equipment, as concretely explained in theanti-theft system in accordance with embodiment 1.

When the registered portable communication equipment 7 exists in theshort-distance wireless communications area in this standby state, thevehicle-mounted communication equipment 6 sends the unlocking enablingsignal to the vehicle control unit 8 while sending the engine startenabling signal to the engine control unit 4. As a result, while the onoperation of an engine key 5 is enabled, the door unlocking mechanism 9operates so as to unlock the doors.

In contrast, when the registered portable communication equipment 7 doesnot exist in the short-distance wireless communications area in theabove-mentioned standby state, the vehicle-mounted communicationequipment 6 does not send the engine start enabling signal to the enginecontrol unit 4, and does not send the unlocking enabling signal to thevehicle control unit 8, either. As a result, while the on operation ofthe engine key 5 is disabled, the door unlocking mechanism 9 does notoperate and keeps the doors in the state where they are locked.

As previously explained, the anti-theft system in accordance withembodiment 3 of the present invention automatically unlocks the doors ofthe vehicle when a person having the registered portable communicationequipment 7 enters an area in which the registered portablecommunication equipment 7 can carry out short-distance wirelesscommunications with the vehicle-mounted communication equipment.Therefore, the unlocking operation becomes unnecessary. On the otherhand, since the unlocking of the doors is not performed even when anyperson who is not having the registered portable communication equipment7 enters the short-distance wireless communications area, the securityagainst theft of the vehicle can be improved.

For example, when the registered portable communication equipment 7exists in the owner's house and the vehicle 1 is parked in the garage ofthe house, if the portable communication equipment 7 exists in an areawhere it can carry out short-distance wireless communications with thevehicle 1 (i.e., the vehicle-mounted communication equipment 6), thedoors of the vehicle may be unlocked unnecessarily. To solve thisproblem, the vehicle control unit 8 can be so constructed as to sendonly the door unlocking enabling signal to the door unlocking mechanism9 in order to allow the user to actually and manually unlock the doors.

Embodiment 4

An anti-theft system in accordance with embodiment 4 of the presentinvention has a function of outputting warning when an engine key 5 hasbeen turned on two or more times in a state in which the operation ofthe engine key is disabled, in addition to the structure of theanti-theft system in accordance with embodiment 1.

FIG. 4 is a block diagram showing the structure of the anti-theft systemin accordance with embodiment 4 of the present invention. Thisanti-theft system is so constructed as to have a modified functioncorresponding to that of the engine control unit 4 of the anti-theftsystem in accordance with embodiment 1, and to additionally include awarning output unit 10. Hereafter, the difference between thisembodiment and embodiment 1 will be explained mainly.

When the on operation of the engine key 5 is carried out a predeterminednumber of times in a state in where no engine start enabling signal hasbeen sent thereto from the vehicle-mounted communication equipment 6,the engine control unit 4 generates a warning control signal and sendsit to the warning output unit 10.

The warning output unit 10 outputs warning with sound and/or light inresponse to the warning control signal from the engine control unit 4.The warning output unit 10 can consist of a speaker which outputs asound, an LED which generates light, etc.

Next, the operation of the anti-theft system in accordance withembodiment 4 of the present invention which is constructed as mentionedabove will be explained.

In a state in which an engine 2 is stopped, the vehicle-mountedcommunication equipment 6 to which a power source is supplied from abattery 3 is on standby while determining whether registered portablecommunication equipment 7 exists in a short-distance wirelesscommunications area in which it can carry out short-distance wirelesscommunications with the vehicle-mounted communication equipment, asconcretely explained in the anti-theft system in accordance withembodiment 1.

When the registered portable communication equipment 7 exists in theshort-distance wireless communications area in this standby state, thevehicle-mounted communication equipment 6 sends an engine start enablingsignal to the engine control unit 4. As a result, the on operation ofthe engine key 5 is enabled.

In contrast, when the registered portable communication equipment 7 doesnot exist in the short-distance wireless communications area in theabove-mentioned standby state, since the vehicle-mounted communicationequipment 6 does not send the engine start enabling signal to the enginecontrol unit 4, the on operation of the engine key 5 is disabled. Inthis state, when the on operation of the engine key 5 has been carriedout two or more times, the engine control unit 4 generates a warningcontrol signal and sends it to the warning output unit 10. As a result,the warning output unit 10 outputs warning with sound and/or light.

As explained above, since the anti-theft system in accordance withembodiment 4 of the present invention outputs warning when any personwho is not carrying the registered portable communication equipment 7has performed the on operation of the engine key 5 two or more times,security against theft of the vehicle can be improved.

The anti-theft system in accordance with this embodiment does not outputany warning immediately after the on operation of the engine key 5 isperformed, unlike related art anti-theft systems. In other words, theanti-theft system in accordance with this embodiment does not output anywarning as long as the on operation of the engine key 5 is not carriedout sequentially two or more times. Therefore, since any warning is notoutputted even if the authorized vehicle user performs the on operationof the engine key 5 carelessly without carrying the registered portablecommunication equipment 7, the usability of the anti-theft system can beimproved.

Embodiment 5

An anti-theft system in accordance with embodiment 5 of the presentinvention has a function of enabling start of an engine under specialconditions even if an authorized vehicle user is not having portablecommunication equipment 7 which is registered therein, in addition tothe structure of the anti-theft system in accordance with embodiment 1.

FIG. 5 is a block diagram showing the structure of the anti-theft systemin accordance with embodiment 5 of the present invention. Thisanti-theft system is so constructed as to have a modified functioncorresponding to that of the engine control unit 4 of the anti-theftsystem in accordance with embodiment 4, and to additionally include arelease code input unit 11. Hereafter, the difference between thisembodiment and embodiment 4 will be explained mainly.

The release code input unit 11 inputs a release code which is defined inadvance. This release code inputted by the release code input unit 11 issent to the engine control unit 4.

In a state in which no engine start enabling signal has been sentthereto from vehicle-mounted communication equipment 6, that is, even ifa person having registered portable communication equipment 7 does notstay in an area in which it can carry out short-distance wirelesscommunications with the vehicle-mounted communication equipment, theengine control unit 4 receives an instruction generated by the onoperation of an engine key 5 and enables itself to start the engine whenthe release code is sent thereto from the release code input unit 1.

Next, the operation of the anti-theft system in accordance withembodiment 5 of the present invention which is constructed as mentionedabove will be explained.

In a state in which the engine 2 is stopped, the vehicle-mountedcommunication equipment 6 to which a power source is supplied from abattery 3 is on standby while determining whether the registeredportable communication equipment 7 exists in a short-distance wirelesscommunications area in which it can carry out short-distance wirelesscommunications with the vehicle-mounted communication equipment, asconcretely explained in the anti-theft system in accordance withembodiment 1.

When the registered portable communication equipment 7 exists in theshort-distance wireless communications area in this standby state, thevehicle-mounted communication equipment 6 sends the engine startenabling signal to the engine control unit 4. As a result, the onoperation of the engine key 5 is enabled.

In contrast, when the registered portable communication equipment 7 doesnot exist in the short-distance wireless communications area in theabove-mentioned standby state, the engine control unit 4 checks to seewhether the release code has been sent thereto from the release codeinput unit 11, and, when determining that the release code has been sentthereto, enables the on operation of the engine key 5. On the otherhand, when determining that the release code has not been sent theretoyet, the engine control unit 4 disables the on operation of the enginekey 5. In this state where the on operation of the engine key 5 isdisabled, when the on operation of the engine key 5 is sequentiallycarried out two or more times, the engine control unit 4 generates awarning control signal and sends it to the warning output unit 10. As aresult, he warning output unit 10 outputs warning with sound and/orlight.

As previously explained, the anti-theft system in accordance withembodiment 5 of the present invention allows even a person who is nothaving the registered portable communication equipment 7 to start theengine 2 when inputting the release code thereto using the release codeinput unit 11. Therefore, when the authorized vehicle user is going todrive the vehicle without carrying the registered portable communicationequipment 7, the authorized vehicle user can drive the vehicle withoutreceiving any warning from the anti-theft system.

This embodiment is useful for not only the case where the authorizedvehicle user is going to drive the vehicle without carrying theregistered portable communication equipment 7, but also a case where thebattery of the portable communication equipment 7 is dead, or a failureoccurs in the portable communication equipment 7. A predetermined timeperiod during which the release code inputted from the release codeinput unit 11 is effective can be provided, and the engine 2 can bestopped when the predetermined time period elapses. This variant canimprove security against theft of the vehicle.

Embodiment 6

An anti-theft system in accordance with embodiment 6 of the presentinvention has a function of enabling the user to input a release code byusing existing operation buttons of vehicle-mounted communicationequipment 6, in addition to the structure of the anti-theft system inaccordance with embodiment 5.

The structure of the anti-theft system in accordance with thisembodiment 6 is the same as that of the anti-theft system in accordancewith embodiment 5 shown in FIG. 5.

The vehicle-mounted communication equipment 6 is provided with two ormore operation buttons not shown. A release code input unit 11 generatesa release code in response to the operation of these operation buttons,and sends it to an engine control unit 4. When a car audio device isused as the vehicle-mounted communication equipment 6, preset memorybuttons for presetting a radio station, which consists of number buttons“1” to “6”, are used as the operation buttons for inputting the releasecode.

In this case, a circuit for controlling the preset memory buttons of thecar audio device can be so constructed as to run from a power sourcealways supplied from the battery 3 of the vehicle 1, like thevehicle-mounted communication equipment 6.

As previously explained, the anti-theft system in accordance withembodiment 6 of the present invention uses the operation buttons whichalready exist in the vehicle-mounted communication equipment 6 as therelease code input unit 11. Therefore, it is not necessary to disposespecial operation buttons in the vehicle-mounted communication equipment6, and the anti-theft system can be constructed at a low cost.

In order to enable the user to input the release code via the existingoperation buttons, the power source from the battery 3 can be suppliednot to the whole of the car audio device, but only to a minimum ofcircuitry required to control the preset memory buttons. In this case,the supply of power to the minimum of circuitry can be stopped when apredetermined time elapses after the power source has been supplied tothe minimum of circuitry according to a predetermined operation and therelease code is inputted by the operation of the operation buttons.According to this structure, since the power consumption can be furtherreduced when the release code input unit 11 is not used, the exhaustionof the battery 3 can be further reduced.

Embodiment 7

An anti-theft system in accordance with embodiment 7 of the presentinvention has a function of outputting warning when an inaccuraterelease code (i.e., an unauthorized release code) has been input two ormore times, in addition to the structure of the anti-theft system inaccordance with embodiment 5.

The structure and operation of the anti-theft system in accordance withthis embodiment 7 are the same as those of the anti-theft system inaccordance with embodiment 5 shown in FIG. 5 except for the operation ofan engine control unit 4. Hereafter, the difference between thisembodiment and embodiment 5 will be explained mainly.

In a state in which no engine start enabling signal has been sentthereto from vehicle-mounted communication equipment 6, that is, whenthe owner having registered portable communication equipment 7 does notstay in an area where it can carry out short-distance wirelesscommunications with the vehicle-mounted communication equipment, theengine control unit 4 generates a warning control signal and sends it toa warning output unit 10 when a release code different from the releasecode pre-stored in the engine control unit 4, i.e., an unauthorizedrelease code has been sent thereto from a release code input unit 11 apredetermined number of times.

Next, the operation of the anti-theft system in accordance withembodiment 7 of the present invention which is constructed as mentionedabove will be explained.

In a state in which an engine 2 is stopped, the vehicle-mountedcommunication equipment 6 to which a power source is supplied from abattery 3 is on standby while determining whether the registeredportable communication equipment 7 exists in the short-distance wirelesscommunications area in which it can carry out short-distance wirelesscommunications with the vehicle-mounted communication equipment, asconcretely explained in the anti-theft system in accordance withembodiment 1.

When the registered portable communication equipment 7 exists in theshort-distance wireless communications area in this standby state, thevehicle-mounted communication equipment 6 sends the engine startenabling signal to the engine control unit 4. As a result, the onoperation of the engine key 5 is enabled.

In contrast, when the registered portable communication equipment 7 doesnot exist in the short-distance wireless communications area in theabove-mentioned standby state, the engine control unit 4 checks to seewhether a release code has been sent thereto from the release code inputunit 11. When then determining that a release code has been sentthereto, the engine control unit 4 checks to see whether or not therelease code matches with the authorized release code. When determiningthat the release code sent thereto is not correct, i.e., it is anunauthorized release code, the engine control unit 4 checks to seewhether a release code has been sent thereto from the release code inputunit 11 again, and, when determining that a release code has been sentthereto, further checks to see whether or not the release code matcheswith the authorized release code.

After repeatedly performing the above-mentioned processing, whendetermining that an unauthorized release code has been sequentially sentthereto two or more times, the engine control unit 4 generates a warningcontrol signal and sends it to the warning output unit 10. As a result,the warning output unit 10 outputs warning with sound and/or light. Onthe other hand, after repeatedly performing the above-mentionedprocessing, when determining that the authorized release code is sentthereto, the engine control unit 4 enables the on operation of theengine key 5.

As previously explained, the anti-theft system in accordance withembodiment 7 of the present invention can allow even a person who is nothaving the registered portable communication equipment 7 to start theengine 2 when inputting the release code thereto using the release codeinput unit 11, while outputting warning when an unauthorized releasecode has been input thereto two or more times, thereby improvingsecurity against theft of the vehicle.

Embodiment 8

An anti-theft system in accordance with embodiment 8 of the presentinvention has a function of enabling the user to register the IDinformation of portable communication equipment 7 into vehicle-mountedcommunication equipment 6 only by performing an easy operation during acommunication connection between the portable communication equipmentand the vehicle-mounted communication equipment, in addition to thestructure of the anti-theft system in accordance with embodiment 1.

FIG. 6 is a block diagram showing the structure of the anti-theft systemin accordance with embodiment 8 of the present invention. Thisanti-theft system is so constructed as to have a modified functioncorresponding to that of the vehicle-mounted communication equipment 6of the anti-theft system in accordance with embodiment 1, and toadditionally include a setting operation unit 12. Hereafter, thedifference between this embodiment and embodiment 1 will be explainedmainly.

The setting operation unit 12 is used in order to provide an instructionfor registering the ID information of the portable communicationequipment 7 into an ID information storage unit 6 a disposed in thevehicle-mounted communication equipment 6. In other words, the settingoperation unit 12 generates a registration instruction in response to amanipulation thereof, and sends it to the vehicle-mounted communicationequipment 6. When a car audio device is used as the vehicle-mountedcommunication equipment 6, operation buttons can be used as the settingoperation unit 12.

In such an initial state as a state in which a vehicle 1 has been onlyrecently purchased, the ID information of any portable communicationequipment 7 is not registered into the ID information storage unit 6 aof the vehicle-mounted communication equipment 6. In this initial state,the vehicle-mounted communication equipment 6 is set up so that it canestablish a communication connection with any portable communicationequipment 7.

Next, the operation of registering the ID information of desiredportable communication equipment 7 into the vehicle-mountedcommunication equipment 6 in the anti-theft system in accordance withembodiment 8 of the present invention which is constructed as mentionedabove will be explained.

When registering the ID information of desired portable communicationequipment 7 into the ID information storage unit 6 a of thevehicle-mounted communication equipment 6, synchronization with thedesired portable communication equipment 7 is established, and acommunication connection with the desired portable communicationequipment 7 is then established in the state in which thevehicle-mounted communication equipment 6 is set up so that it canestablish a communication connection with any portable communicationequipment 7. When the setting operation unit 12 is manipulated in thisstate, the registration instruction is sent to the vehicle-mountedcommunication equipment 6. When receiving the registration instructionfrom the setting operation unit 12, the vehicle-mounted-communicationequipment 6 acquires the ID information from the portable communicationequipment 7, and then stores it in the ID information storage unit 6 a.The process of registering the ID information of the desired portablecommunication equipment 7 into the vehicle-mounted communicationequipment 6 is thus completed.

As previously explained, the anti-theft system in accordance withembodiment 8 of the present invention allows the user to register the IDinformation of portable communication equipment 7 into thevehicle-mounted communication equipment 6 by simply manipulating thesetting operation unit 12 during a communication connection between thevehicle-mounted communication equipment 6 and the portable communicationequipment 7.

Embodiment 9

An anti-theft system in accordance with embodiment 9 of the presentinvention has a function of enabling the user to erase ID informationregistered into vehicle-mounted communication equipment 6, in additionto the structure of the anti-theft system in accordance with embodiment1.

FIG. 7 is a block diagram showing the structure of the anti-theft systemin accordance with embodiment 9 of the present invention. Thisanti-theft system is so constructed as to have a modified functioncorresponding to that of the vehicle-mounted communication equipment 6of the anti-theft system in accordance with embodiment 1, and toadditionally include an erase code input unit 13. Hereafter, thedifference between this embodiment and embodiment 1 will be explainedmainly.

The erase code input unit 13 is comprised of special-purpose keys, andis used in order for the user to input an erase code, which is definedin advance, into the system. The erase code inputted into the system bythis erase code input unit 13 is sent to the vehicle-mountedcommunication equipment 6. For example, when a car audio device is usedas the vehicle-mounted communication equipment 6, operation buttons ofthe car audio device can be used as the erase code input unit 13. Inthis case, since the special-purpose keys which serve as the erase codeinput unit become unnecessary, the anti-theft system can be constructedat a low cost.

In response to the erase code sent thereto from the erase code inputunit 13, the vehicle-mounted communication equipment 6 erases the IDinformation stored in an ID information storage unit 6 a.

Next, the operation of erasing the ID information registered into thevehicle-mounted communication equipment 6 in the anti-theft system inaccordance with embodiment 9 of the present invention which isconstructed as mentioned above will be explained.

When erasing the ID information registered into the ID informationstorage unit 6 a of the vehicle-mounted communication equipment 6, theuser causes the anti-theft system to shift to erasing mode by providinga predetermined instruction to the vehicle-mounted communicationequipment 6 first. In this state, the user manipulates the erase codeinput unit 13 so as to input the erase code into the anti-theft system.This erase code inputted into the anti-theft system by the erase codeinput unit 13 is then sent to the vehicle-mounted communicationequipment 6. In response to the erase code from the erase code inputunit 13, the vehicle-mounted communication equipment 6 erases the IDinformation stored in the ID information storage unit 6 a. When theprocess of erasing the ID information registered into thevehicle-mounted communication equipment 6 is thus completed, thevehicle-mounted communication equipment 6 is placed in the initialstate.

As previously explained, the anti-theft system in accordance withembodiment 9 of the present invention erases the ID informationregistered into the vehicle-mounted communication equipment 6 inresponse to easy manipulation of the erase code input unit 13.Therefore, the ID information can be easily erased. In addition, sincethe anti-theft system returns to the initial state when the IDinformation registered into the vehicle-mounted communication equipment6 is erased, conditions under which the ID information of other portablecommunication equipment 7 can be newly registered into thevehicle-mounted communication equipment are satisfied. The newregistration of the ID information of portable communication equipment 7can be implemented by the method explained in above-mentioned embodiment8.

Embodiment 10

An anti-theft system in accordance with embodiment 10 of the presentinvention has a function of enabling the user to erase ID informationregistered into vehicle-mounted communication equipment 6 only during acommunication connection between the vehicle-mounted communicationequipment and portable communication equipment, in addition to thestructure of the anti-theft system in accordance with embodiment 9.

The structure and operation of the anti-theft system in accordance withthis embodiment 7 are the same as those of the anti-theft system inaccordance with embodiment 9 shown in FIG. 7 except for the operation ofthe vehicle-mounted communication equipment 6. Hereafter, the differencebetween this embodiment and embodiment 9 will be explained mainly.

In a state in which a communication connection is established betweenthe vehicle-mounted communication equipment 6 and the portablecommunication equipment 7, the vehicle-mounted communication equipment 6erases the ID information stored in an ID information storage unit 6 ain response to an erase code sent thereto from an erase code input unit13.

Next, the operation of erasing the ID information registered into thevehicle-mounted communication equipment 6 in the anti-theft system inaccordance with embodiment 10 of the present invention which isconstructed as mentioned above will be explained.

When erasing the ID information registered into the ID informationstorage unit 6 a of the vehicle-mounted communication equipment 6, theuser causes the anti-theft system to shift to erasing mode by providinga predetermined instruction to the vehicle-mounted communicationequipment 6 first. In this state in which the anti-theft system isplaced in the erasing mode, synchronization between the registeredportable communication equipment 7 and the vehicle-mounted communicationequipment 6 is established, and a communication connection between themis then established. In this state in which a communication connectionis established between them, the user manipulates the erase code inputunit 13 so as to input an erase code into the system. This erase codeinputted into the system by the erase code input unit 13 is then sent tothe vehicle-mounted communication equipment 6. In response to the erasecode from the erase code input unit 13, the vehicle-mountedcommunication equipment 6 erases the ID information stored in the IDinformation storage unit 6 a on conditions that a communicationconnection between the registered portable communication equipment 7 andthe vehicle-mounted communication equipment 6 is established. Theprocess of erasing the ID information registered into thevehicle-mounted communication equipment 6 is thus completed.

As previously explained, the anti-theft system in accordance withembodiment 10 of the present invention can erase the ID informationregistered into the vehicle-mounted communication equipment 6 only whenthe erase code is inputted from the erase code input unit 13 during acommunication connection between the registered portable communicationequipment 7 and the vehicle-mounted communication equipment 6.Therefore, the ID information cannot be erased even if a third party whois not having the registered portable communication equipment 7 causesthe erase code input unit to input the erase code into the system. As aresult, the anti-theft system in accordance with this embodiment canprevent any third party from erasing the ID information fraudulently.

Embodiment 11

An anti-theft system in accordance with embodiment 11 of the presentinvention has a function of outputting warning when onlyyet-to-be-registered portable communication equipment which does nothave ID information registered into the system continues staying in thevicinity of vehicle-mounted communication equipment 6 for apredetermined time period or more, in addition to the structure of theanti-theft system in accordance with embodiment 1.

FIG. 8 is a block diagram showing the structure of the anti-theft systemin accordance with embodiment 11 of the present invention. Thisanti-theft system is so constructed as to have a modified functioncorresponding to that of the vehicle-mounted communication equipment 6of the anti-theft system in accordance with embodiment 1, and toadditionally include a warning output unit 14. Hereafter, the differencebetween this embodiment and embodiment 1 will be explained mainly.

When registered portable communication equipment 7 does not exist in anarea where it can carry out short-distance wireless communications withthe vehicle-mounted communication equipment 6 and yet-to-be-registeredportable communication equipment 7 c which does not have ID informationregistered into the system continues staying in the vicinity of thevehicle-mounted communication equipment 6 for a predetermined timeperiod or more, the vehicle-mounted communication equipment 6 generatesa warning control signal and sends it to the warning output unit 14.

The warning output unit 14 outputs warning with sound and/or light inresponse to the warning control signal from the vehicle-mountedcommunication equipment 6. The warning output unit 14 can consist of aspeaker which outputs a sound, an LED which generates light, etc. Thiswarning outputted from the warning output unit 14 can consist of such anannouncement as “An anti-theft system is mounted in this vehicle”.

Next, the operation of the anti-theft system in accordance withembodiment 11 of the present invention which is constructed as mentionedabove will be explained.

In a state in which an engine 2 is stopped, the vehicle-mountedcommunication equipment 6 to which a power source is supplied from abattery 3 is on standby while determining whether the registeredportable communication equipment 7 exists in a short-distance wirelesscommunications area in which it can carry out short-distance wirelesscommunications with the vehicle-mounted communication equipment, asconcretely explained in the anti-theft system in accordance withembodiment 1.

When the registered portable communication equipment 7 exists in theshort-distance wireless communications area in this standby state, thevehicle-mounted communication equipment 6 sends an engine start enablingsignal to an engine control unit 4. As a result, the on operation of anengine key 5 is enabled.

In contrast, when the registered portable communication equipment 7 doesnot exist in the short-distance wireless communications area andyet-to-be-registered portable communication equipment 7 c continuesstaying in the vicinity of the vehicle-mounted communication equipment 6for a predetermined time period or more, the vehicle-mountedcommunication equipment 6 generates the warning control signal and sendsit to the warning output unit 14. As a result, the warning output unit14 outputs warning with sound and/or light.

As previously explained, the anti-theft system in accordance withembodiment 11 of the present invention outputs warning when a person whois not carrying the registered portable communication equipment 7continues staying in the vicinity of the vehicle 1 (i.e., thevehicle-mounted communication equipment 6) for a predetermined timeperiod or more. Therefore, the anti-theft system can protect the vehiclefrom illegal acts (e.g., prevent the vehicle from being ransacked) by athird party, thereby improving the security.

The anti-theft system can be so constructed as to select, as the time ofoutputting warning, “only at designated times”, “only at night”, or thelike. According to this structure, the anti-theft system can deal with acase where the user desires to disable the function of outputtingwarning.

Embodiment 12

An anti-theft system in accordance with embodiment 12 of the presentinvention has a function of checking to see whether vehicle-mountedcommunication equipment can carry out communications with registeredportable communication equipment 7 at predetermined intervals while avehicle 1 is moving, and outputting warning when determining that thevehicle-mounted communication equipment cannot carry out communicationswith the registered portable communication equipment 7, in addition tothe structure of the anti-theft system in accordance with embodiment 1.

FIG. 9 is a block diagram showing the structure of the anti-theft systemin accordance with embodiment 12 of the present invention. Thisanti-theft system is so constructed as to have a modified functioncorresponding to that of the vehicle-mounted communication equipment 6of the anti-theft system in accordance with embodiment 1, and toadditionally include a warning output unit 15. Hereafter, the differencebetween this embodiment and embodiment 1 will be explained mainly.

The vehicle-mounted communication equipment 6 checks to see whether itcan carry out communications with the registered portable communicationequipment 7 at predetermined intervals while the vehicle 1 is moving,and generates and outputs a warning control signal to the warning outputunit 14 when determining that the vehicle-mounted communicationequipment cannot carry out communications with the registered portablecommunication equipment 7. The anti-theft system determines whether ornot the vehicle 1 is moving based on a speed signal acquired from aspeed sensor not shown.

The warning output unit 15 outputs warning with sound and/or light inresponse to the warning control signal from the vehicle-mountedcommunication equipment 6. The warning output unit 14 can consist of aspeaker which outputs a sound, an LED which generates light, etc. Thiswarning outputted from the warning output unit 14 can consist of anannouncement “This is a stolen car”, a blast of a horn, or the like.

Next, the operation of the anti-theft system in accordance withembodiment 12 of the present invention which is constructed as mentionedabove will be explained.

In a state in which an engine 2 has been started, the vehicle-mountedcommunication equipment 6 is on standby while determining whether theregistered portable communication equipment 7 exists in a short-distancewireless communications area in which it can carry out short-distancewireless communications with the vehicle-mounted communicationequipment. When determining that the vehicle 1 is moving in this standbystate, the vehicle-mounted communication equipment 6 checks to seewhether it can carry out communications with the registered portablecommunication equipment 7.

When, in the above-mentioned checking step, determining that it isimpossible to carry out communications with the registered portablecommunication equipment 7, the vehicle-mounted communication equipment 6generates a warning control signal, and sends it to the warning outputunit 14. As a result, the warning output unit outputs warning with soundand/or light.

As previously explained, the anti-theft system in accordance withembodiment 12 of the present invention outputs warning when a person whois not carrying the registered portable communication equipment 7 hasdriven the vehicle 1 (i.e., the vehicle-mounted communication equipment6). Therefore, when the driver leaves from the vehicle 1 temporarilywhile having the registered portable communication equipment 7 with theengine at an idle, and the vehicle is then stolen, for example, theanti-theft system makes an announcement “This is a stolen car”, orblasts a horn if the vehicle 1 moves, so as to notify those around-themoving vehicle that the vehicle has been stolen.

Embodiment 13

An anti-theft system in accordance with embodiment 12 of the presentinvention has a function of checking to see whether vehicle-mountedcommunication equipment can carry out communications with registeredportable communication equipment 7 at predetermined intervals while avehicle 1 is moving, and outputting warning when determining that thestate in which the vehicle-mounted communication equipment cannot carryout communications with the registered portable communication equipment7 has lasted for a predetermined time period or more, in addition to thestructure of the anti-theft system in accordance with embodiment 12.

The structure and operation of the anti-theft system in accordance withthis embodiment 13 are the same as those of the anti-theft system inaccordance with embodiment 12 shown in FIG. 9 except for the operationof the vehicle-mounted communication equipment 6. Hereafter, thedifference between this embodiment and embodiment 12 will be explainedmainly.

While the vehicle 1 is moving, the vehicle-mounted communicationequipment 6 checks to see whether it can carry out communications withthe registered portable communication equipment 7, and, when determiningthat the state in which the vehicle-mounted communication equipmentcannot carry out communications with the registered portablecommunication equipment 7 has lasted for a predetermined time period ormore, generates a warning control signal and sends it to a warningoutput unit 14.

Next, the operation of the anti-theft system in accordance withembodiment 13 of the present invention which is constructed as mentionedabove will be explained.

In a state in which an engine 2 has been started, the vehicle-mountedcommunication equipment 6 is on standby while determining whether theregistered portable communication equipment 7 exists in a short-distancewireless communications area in which it can carry out short-distancewireless communications with the vehicle-mounted communicationequipment. When determining that the vehicle 1 is moving in this standbystate, the vehicle-mounted communication equipment 6 checks to seewhether it can carry out communications with the registered portablecommunication equipment 7.

When, in the above-mentioned checking step, determining that it isimpossible to carry out communications with the registered portablecommunication equipment 7, the vehicle-mounted communication equipment 6checks to see whether the state in which it is impossible to carry outcommunications with the registered portable communication equipment haslasted for the predetermined time period or more. When then determiningthat the state in which it is impossible to carry out communicationswith the registered portable communication equipment has lasted for thepredetermined time period or more, the vehicle-mounted communicationequipment generates the warning control signal and sends it to thewarning output unit 14. As a result, the warning output unit outputswarning with sound and/or light.

As previously explained, the anti-theft system in accordance withembodiment 13 of the present invention outputs warning when a person whois not carrying the registered portable communication equipment 7 hasdriven the vehicle 1 (i.e., the vehicle-mounted communication equipment6), that is, when a state in which the registered portable communicationequipment 7 is not moving together with the vehicle 1 has lasted for apredetermined time period. Therefore, as previously explained inembodiment 5, when the authorized vehicle user brings the vehicle to astate in which the user can drive the vehicle by inputting a releasecode into the anti-theft system without having the portablecommunication equipment 7, for example, the anti-theft system does notoutput any warning within the predetermined time period. Accordingly, insuch a case as “a bit of shopping” in neighboring stores, since the userdoesn't need to carry the registered portable communication equipment 7,the anti-theft system affords convenience to the user.

Embodiment 14

An anti-theft system in accordance with embodiment 14 of the presentinvention has a function of outputting no warning when vehicle-mountedcommunication equipment can carry out communications with portablecommunication equipment (referred to as portable communication equipmentwith registration history) which was registered in the past into theanti-theft system while the vehicle-mounted communication equipmentcannot carry out communications with registered portable communicationequipment 7, in addition to the structure of the anti-theft system inaccordance with embodiment 13.

FIG. 10 is a block diagram showing the structure of the anti-theftsystem in accordance with embodiment 14 of the present invention. Thisanti-theft system is so constructed as to have a modified functioncorresponding to that of the vehicle-mounted communication equipment 6of the anti-theft system in accordance with embodiment 1, and toadditionally include a warning output unit 15. Hereafter, the differencebetween this embodiment and embodiment 1 will be explained mainly.

The vehicle-mounted communication equipment 6 is provided with aregistration history storage unit 6 c for storing ID information whichwas stored in the past in an ID information storage unit 6 a. Thevehicle-mounted communication equipment 6 checks to see whether it cancarry out communications with the registered portable communicationequipment 7 while the vehicle 1 is moving, and, when determining that itcannot carry out communications with the registered portablecommunication equipment 7, further checks to see whether it can carryout communications with any portable communication equipment withregistration history 7 d having ID information which is stored in theregistration history storage unit 6 c. When determining that it isimpossible to carry out communications with any portable communicationequipment with registration history 7 d, the vehicle-mountedcommunication equipment generates a warning control signal and sends itto the warning output unit 14. The anti-theft system determines whetheror not the vehicle 1 is moving based on a speed signal acquired from aspeed sensor not shown. The warning output unit 15 operates in the sameway that that of embodiment 12 does.

Next, the operation of the anti-theft system in accordance withembodiment 14 of the present invention which is constructed as mentionedabove will be explained.

In a state in which an engine 2 has been started, the vehicle-mountedcommunication equipment 6 is on standby while determining whether theregistered portable communication equipment 7 exists in a short-distancewireless communications area in which it can carry out short-distancewireless communications with the vehicle-mounted communicationequipment. When determining that the vehicle 1 is moving in this standbystate, the vehicle-mounted communication equipment 6 checks to seewhether it can carry out communications with the registered portablecommunication equipment 7.

When, in the above-mentioned checking step, determining that it isimpossible to carry out communications with the registered portablecommunication equipment 7, the vehicle-mounted communication equipment 6further checks to see whether it can carry out communications with anyportable communication equipment with registration history 7 d having IDinformation which is stored in the registration history storage unit 6c. When determining that it is impossible to carry out communicationswith any portable communication equipment with registration history 7 d,the vehicle-mounted communication equipment generates a warning controlsignal and sends it to the warning output unit 14. As a result, thewarning output unit outputs warning with sound and/or light.

As previously explained, the anti-theft system in accordance withembodiment 14 of the present invention can avoid the output of warningwhen the user is carrying other portable communication equipment whichwas registered in the past into the anti-theft system after, forexample, replacing the registered portable communication equipmentregistering with another family member's portable communicationequipment.

Embodiment 15

An anti-theft system in accordance with embodiment 15 of the presentinvention has a function of outputting pre-warning before outputtingwarning, in addition to the structure of the anti-theft system inaccordance with embodiment 4.

FIG. 11 is a block diagram showing the structure of the anti-theftsystem in accordance with embodiment 15 of the present invention. Thisanti-theft system is so constructed as to include a pre-warning outputunit 16 in addition to the structure of the anti-theft system inaccordance with embodiment 14. Hereafter, the difference between thisembodiment and embodiment 4 will be explained mainly.

In a state in which no engine start enabling signal has been sentthereto from vehicle-mounted communication equipment 6, an enginecontrol unit 4 generates a pre-warning control signal and sends it tothe pre-warning output unit 16 when the on operation of an engine key 5is carried out.

The pre-warning output unit 16 outputs pre-warning with sound and/orlight in response to the pre-warning control signal from the enginecontrol unit 4. The pre-warning output unit 16 can consist of a speakerwhich outputs a sound, an LED which generates light, etc.

Next, the operation of the anti-theft system in accordance withembodiment 4 of the present invention which is constructed as mentionedabove will be explained.

In a state in which an engine 2 is stopped, the vehicle-mountedcommunication equipment 6 to which a power source is supplied from abattery 3 is on standby while determining whether registered portablecommunication equipment 7 exists in a short-distance wirelesscommunications area in which it can carry out short-distance wirelesscommunications with the vehicle-mounted communication equipment, asconcretely explained in the anti-theft system in accordance withembodiment 1.

When the registered portable communication equipment 7 exists in theshort-distance wireless communications area in this standby state, thevehicle-mounted communication equipment 6 sends the engine startenabling signal to the engine control unit 4. As a result, the onoperation of the engine key 5 is enabled.

In contrast, when the registered portable communication equipment 7 doesnot exist in the short-distance wireless communications area in theabove-mentioned standby state, since the vehicle-mounted communicationequipment 6 does not send the engine start enabling signal to the enginecontrol unit 4, the on operation of the engine key 5 is disabled. Inthis state, when the on operation of the engine key 5 is carried out,the engine control unit 4 generates a pre-warning control signal andsends it to the pre-warning output unit 16. As a result, the pre-warningoutput unit outputs pre-warning such as an announcement “Stop theillegal act immediately”, for example.

After that, when the on operation of the engine key 5 is carried out apredetermined number of times, the engine control unit 4 generates awarning control signal and sends it to the warning output unit 10. As aresult, the warning output unit outputs warning which is conspicuous forthose around the vehicle, by, for example, blasting a horn.

As previously explained, the anti-theft system in accordance withembodiment 15 of the present invention outputs warning after outputtingpre-warning. There is a possibility that sudden warning, such as a blastof a horn, or notification of an announcement “This car is stolen” tothose around the vehicle, confuses the driver and hence interferes withsafe driving. In contrast, the stepwise warning output process includingthe step of outputting pre-warning and the step of outputting warningcan avoid such a situation. By performing the step of outputtingpre-warning with such an announcement as “This car has theft preventionfunction” or “You are doing illegal act”, the rate of theft preventioncan be raised and the security against theft of the vehicle can beimproved.

The function of outputting pre-warning before outputting warning can bealso applied to the anti-theft system which outputs warning inaccordance with any one of above-mentioned embodiments 7, 11, 12, 13,and 14.

INDUSTRIAL APPLICABILITY

As mentioned above, the anti-theft system in accordance with the presentinvention is suitable for surely preventing any person other than anauthorized vehicle user from starting the engine of a vehicle and makingit possible to take measures against theft of the vehicle with an easyoperation.

1. An anti-theft system comprising: an engine control unit for starting an engine in response to an on operation of an engine key only when an engine start enabling signal is supplied thereto; portable communication equipment which is used for short-distance wireless communications, and to which peculiar ID information is provided; and vehicle-mounted communication equipment having an ID information storage unit for registering the peculiar ID information provided to said portable communication equipment thereinto, for acquiring the ID information from said portable communication equipment via short-distance wireless communications regardless of whether the on operation of said engine key has been carried out, and for stopping the supply of said engine start enabling signal to said engine control unit when the acquired ID information does not match with the ID information registered into said ID information storage unit.
 2. The anti-theft system according to claim 1, characterized in that the short-distance wireless communications are carried out using a radio transmission method according to Bluetooth standards.
 3. The anti-theft system according to claim 1, characterized in that said system further includes a vehicle control unit for unlocking a door of the vehicle in response to an unlocking enabling signal for allowing unlocking of the door, and said vehicle-mounted communication equipment supplies said unlocking enabling signal to said vehicle control unit when ID information which matches with the ID information acquired from said portable communication equipment via short-distance wireless communications is registered into the ID information storage unit.
 4. The anti-theft system according to claim 1, characterized in that the engine control unit also generates a warning output when the on operation of the engine key is carried out two or more times in a state in which the ID information acquired from the portable communication equipment via short-distance wireless communications does not match with the ID information registered into the ID information storage unit.
 5. The anti-theft system according to claim 1, characterized in that said system further includes a release code input unit for inputting a release code into the engine control unit, and said engine control unit starts the engine in response to the on operation of the engine key when the release code is inputted thereto from said release code input unit even if said engine control unit is placed in a state in which the engine start enabling signal is not supplied thereto.
 6. The anti-theft system according to claim 5, characterized in that existing operation buttons of the vehicle-mounted communication equipment are used as the release code input unit, and the release code input unit generates the release code according to a manipulation of said operation buttons and sends the release code to the engine control unit.
 7. The anti-theft system according to claim 5, characterized in that the engine control unit generates a warning output when an unauthorized release code is sequentially input thereto from the release code input unit two or more times.
 8. The anti-theft system according to claim 1, characterized in that the vehicle-mounted communication equipment has an operation button, and acquires ID information from the portable communication equipment and registers the ID information into the ID information storage unit when said operation button is manipulated in a state in which the vehicle-mounted communication equipment carries out short-distance wireless communications with the portable communication equipment.
 9. The anti-theft system according to claim 1, characterized in that said system further includes an erase code input unit for inputting an erase code into the vehicle-mounted communication equipment, and said vehicle-mounted communication equipment erases the ID information stored in the ID information storage unit in response to the erase code inputted from said erase code input unit.
 10. The anti-theft system according to claim 9, characterized in that the vehicle-mounted communication equipment erases the ID information stored in the ID information storage unit in response to the erase code from the erase code input unit only when the vehicle-mounted communication equipment is placed in a state in which it carries out short-distance wireless communications with the portable communication equipment.
 11. The anti-theft system according to claim 1, characterized in that the vehicle-mounted communication equipment generates a warning output when only portable communication equipment other than the portable communication equipment having the ID information registered into the ID information storage unit exists in an area in which it can carry out short-distance wireless communications with the vehicle-mounted communication equipment for a predetermined time period or more.
 12. The anti-theft system according to claim 1, characterized in that the vehicle-mounted communication equipment generates a warning output when the portable communication equipment having the ID information registered into the ID information storage unit is not moving together with the vehicle.
 13. The anti-theft system according to claim 1, characterized in that the vehicle-mounted communication equipment generates a warning output when a state in which the portable communication equipment having the ID information registered into the ID information storage unit is not moving together with the vehicle lasts for a predetermined time period.
 14. The anti-theft system according to claim 1, characterized in that the vehicle-mounted communication equipment generates a warning output when portable communication equipment having ID information which has not been registered into the ID information storage unit yet is moving together with the vehicle.
 15. The anti-theft system according to claim 4, characterized in that the vehicle-mounted communication equipment generates a pre-warning output before generating the warning output. 